The present invention relates to systems and apparatus for telecommunications cabinets and particularly to systems and apparatus for upgrading inservice telecommunications cabinets.
During deregulation of the telecommunications industry in the early 1980""s many thousands of telecommunications cabinets were installed to support the expansion of the phone network. These cabinets were typically placed near urban developments by the telephone companies to provide local access and contained telecommunications equipment.
Since the initial installation and population of these cabinets, telecommunications equipment has advanced. In particular, phone systems have evolved to provide significantly higher line density. In order to provide adequate voice and data systems to their urban customers, local access providers and Incumbent Local Exchanger Carriers (ILEC) need to upgrade the equipment in the local telecommunications cabinets with state of the art equipment, including, but not limited to, Digital Loop Carrier (DLC), and Digital Subscriber Loop systems (xDSL). However, they face a number of problems. The new equipment has greater line density and it requires more power, cooling and space than existing cabinets can provide. The new equipment also emits significantly more electromagnetic radiation than the old equipment and may violate FCC regulations on EMI emissions if run in existing cabinets. In addition, most of the existing or legacy cabinets can only accommodate electronics racks that are twelve inches or less in depth. Some of newer electronics racks are more than thirteen inches in depth and therefore they cannot fit in legacy cabinets.
Replacing the existing telecommunications cabinets with new ones designed to accommodate the need for greater line density, and increased power, cooling, space and EMI requirements of the new equipment is a problem too. If a cabinet is removed and replaced, a new right of way is required. This is both costly and time consuming, especially in more densely populated areas like the North Eastern United States, where many municipalities and townships have become significantly more resistant to any form of development.
Moreover, if a new cabinet is installed, there has to be continuity of service to existing customers during the installation. In a new installation, this is usually accomplished by first transferring all the lines to a mirror set of telecommunications equipment in a trailer. After the new cabinet is set up, the lines are then all transferred back to the new cabinet. This procedure is both very costly and time consuming.
What is needed is a way to utilize the existing cabinets and their existing rights of way, by upgrading the legacy cabinets to be capable of accommodating the new equipment requirements. This upgrade should not only be cost effective, but should preferably be able to be done with minimal disruption of service.
The present invention is a cabinet upgrade system for in-service or legacy telecommunications cabinets that improves the existing cabinet""s power, cooling, space and EMI capabilities, thereby allowing the cabinet to be used to house updated telecommunications equipment.
In one embodiment, the invention includes an extension collar that fits on the legacy cabinet in place of the legacy doors. The extension collar allows the attachment of replacement doors that have heat exchanger units integrated into them. The extension collar also has suitable flanges to accept Electro-magnetic Interference (EMI) gaskets and so provide EMI shielding capable of meeting standards, such as but not limited to Federal Communications Commission (FCC) mandated levels. The extension collar also has suitable flanges to accept weather or environmental gaskets and so provide protection from the elements.
In the preferred embodiment of the invention the replacement doors are heat exchanger doors. The doors have one or more sets of fans, or other air moving means, incorporated into them. The purpose of the fans is to set up two sets of air circulation, one using internal air and one using external air. Both air circulations flow past a common heat-conducting, heat-exchanger partition. By this means heat from within the cabinet is transferred out into the surrounding atmosphere without any exchanger of air and the associated problems of filtering that air exchanger necessitates.
Many legacy cabinets are raised off the ground by up to fourteen inches or so. This is done to avoid flooding of the equipment compartment. One embodiment of the invention takes advantage of the resultant space beneath legacy cabinets to accommodate a bulk power upgrade in the form of a battery chamber. As part of the upgrade to the cabinet, a battery chamber is fitted beneath the base of legacy cabinet. Batteries are indifferent to flooding, so long as the water does not reach the terminals, which are located at the top of the battery chambers and close to the base of the legacy equipment compartment base. The heat exchanger doors are constructed to extend down below the base of the cabinet""s equipment compartment and have inlet vents that draw in air from beneath the level of the legacy cabinet equipment compartment base. Furthermore, one of the doors"" external air inlets is directed so as to draw air through the upgrade battery cabinet. This allows both cooling and venting of the battery chamber, both of which contribute to longer battery life. Having one door draw external air through the battery chamber while the other draws air in from vents directed away from the chamber ensures that there is enough, but not too much air drawn through the battery compartment. Too much air might result in dust being drawn into the battery compartment.